Core barrel closure for sonic drill



8- ,1970 J. E. HOLZMAN 3,525,409

CORE BARREL CLOSURE FOR SONIC DRILL Filed Dec. 12, 1968 FIG. 2

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J. E. HOLZMAN HIS ATTORNEY United States Patent 01 3,525,409 Patented Aug. 25, 1970 3,525,409 CORE BARREL CLOSURE FOR SONIC DRILL Johnston E. Holzman, La Jolla, Calif., assignor to Shell Oil Company, New York, N.Y., a corporation of Delaware Filed Dec. 12, 1968, Ser. No. 783,240 Int. Cl. E21b 9/20, 25/00 US. Cl. 175-245 4 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION This invention relates generallyto the art of soil coring or sample taking, and pertains more particularly to a method and apparatus particularly adaptable for sonic drills for retrieving cores and samples from unconsolidated formations.

Core retention for unconsolidated materials such as soil, placer gravels, phosphate sands, ocean floor sediments, etc., has always been a major problem. Prior art devices have attempted to overcome this difiiculty by packing the materials so tightly in the barrel that it will be retained by side friction, aided by various kinds of spring-type core catchers. Such prior art methods and apparatus are useless with sonic drills because vibration greatly reduces friction both inside and outside the core barrel.

SUMMARY OF THE INVENTION It is therefore a primary object of the present invention to provide means for retaining core samples that permit the utilization of the extreme fast sonic method of drillings.

It is a further object of the present invention to provide improved core retention means that is usable with a sonic drill.

Briefly, in accordance with the present invention a flexible lining is fitted within the barrel of the sonicallydriven coring drill with means responsive to the drag of an anchor for closing the lower end of said lining upon the beginning of withdrawal of the core barrel from a test hole.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and advantages of the present invention will become apparent to those skilled in the art from the following description when read in conjunction with the accompanying drawing, in which:

FIG. 1 is a side elevation partially in section of a sonic coring drill in accordance with the present invention;

FIG. 2 is a detailed view in section of the closure apparatus of the present invention; I

FIG. 3 is a side view in section of the apparatus of FIG. 1 in the closed position;

FIG. 4 is a detailed view of a portion of the apparatus of FIG. 2; and

FIG. 5 is a detailed view of a portion of the apparatus of FIG. 3.

DETAILED DESCRIPTION OF THE DRAWINGS Referring now to the drawings and more particularly to FIG. 1, there is illustrated a sonic coring drill comprising a sonic oscillator designated by the numeral 11 which is operatively coupled by means of suitable clamp 12 or otherwise to a tubular drill string 13. Briefly, alternately-directed vertical oscillators generated by the oscillator 11 set up elastic standing wave vibrations in the drill string 13. The lower end of the drill string rapidly forces itself into the ground when rested thereon. A more thorough description of the operation of such drills may be obtained with reference to US. Pat. No. 3,194,326, issued July 13, 1965 to A. G. Bodine, I r.

In FIG. 2 is illustrated in detail the closure apparatus of the present invention. As illustrated in FIG. 2, a drill string or coring barrel 13 is provided internally with a flexible tubular lining extending from the lower end thereof upward for sufficient distance to encompass the desired sample. The inner lining or sleeve 14 may be constructed of any suitable flexible material, such as rubber or neoprene. Such linings are commercially available. In accordance with the preferred embodiment a noose of suitable strength cord or wire 15 encircles lining 14 a short distance from the lower end thereof and is retained in position by suitable means, such as a circumferential groove 16 in lining member 14. The string of wire 15 is provided with a slip-knot loop 17 in one end thereof. The other end of string or Wire 15 extends through to the slip loop 17 through a jam-cleat or one-way clamping apparatus 18 attached in any suitable manner to the lower end of core barrel 13 and is connected by suitable releasable means such as a soft shear pin or plug 19 to anchor member 20. The anchor member 20 serves also as a drive shoe, being annular in form and having an abutment or shoulder 21 engageable by the lower end of the core barrel 13.

OPERATION In carrying out the present invention, a suitable core barrel is provided with a flexible lining enclosure means as illustrated in FIG. 2 and discussed above. The coring barrel is then sonically driven as described above to the desired depth in a selected formation. Upon reaching the desired depth downward force on coring barrel 13 is relieved and sufficient upward force applied to remove the barrel while vibrations are maintained therein. Upward movement of barrel 13 immediately uncouples vibrations therein from anchor 20 leaving it frictionally anchored in place in the formation as loose earth material flows in, as shown in FIG. 3, to further anchor it in place. Continued upward movement draws the noose 15 tightly around flexible lining 14, thus closing it ofl, as shown in FIG. 3. As soon as the upward force exceeds the strength limits of shear pin 19, the lower end of cord or noose 15 is then immediately released from anchor 20 and the noose is held in place in tightly closed position by a jam-cleat or one-way clamp 18 tightly engaging cord 15. As soon as the core barrel is removed from the formation, the lining may then be removed with the core sample maintained in place.

While my invention has been described with respect to a specific embodiment, it will be apparent to those skilled in the art that many changes and modifications may be made in the illustrated apparatus without departing from the scope of the present invention as defined in the appended claims.

I claim as my invention:

1. A core barrel closure for a sonic drill, said apparatus comprising:

an elongated hollow core barrel;

a flexible lining fitting within the bore of said barrel;

anchor means engageable by the lower end of said barrel to be driven ahead thereof; and

restricting means operatively connected to said anchor means for closing the lower end of said lining when the lower end of said core barrel is moved away from said anchor means.

2. Core retaining means for use in combination with a non-rotating coring barrel, said means comprising:

a flexible tubular lining for lining the interior of said barrel;

a closure means engaging the lower end of said lining and operable to engage and restrict said end to prevent the escape of material therefrom;

anchor means operatively engageable and driven by the lower end of said barrel; and

connecting means operatively connecting said closure means to said anchor means whereby said closure means is actuated by pulling the lower end of said barrel away from said anchor means.

3. The apparatus of claim 2 wherein said closure means comprises a noose encircling the lower end of said lining.

4. The apparatus of claim 2 wherein said anchor means comprises an annular drive bit loosely fitted to the lower end of said core barrel.

References Cited UNITED STATES PATENTS 1,552,755 9/1925 Pyron 175-243 X 2,126,684 8/1938 Humason 175243 X 2,347,726 5/1944 Auld et a1 175243 X 2,927,776 3/ 1960 Hildebrandt 175245 X 3,008,529 11/1961 Lynch et al. 175---243 3,285,354 11/1966 Sanders et al 175245 DAVID H. BROWN, Primary Examiner R. E. FAVREAU, Assistant Examiner US. Cl. X.R. 175-243 

